Article supports or shackles are in common use on poultry and fowl processing lines. One example is described in European patent EP 0786208, which discloses a shackle assembly for suspending poultry carcasses by their legs for movement along a conveyor track. The track defines a processing path of a poultry processing line and suspended carcasses engage various processing stations along the line as the carcasses move along the processing path. More specifically, a plurality of carriages are supported in spaced relationship and moved along the conveyor track by a transport chain. Shackles are rotatably mounted with respect to the carriages and a turning block associated and rotatable with each shackle is adapted to cooperate with features along the processing path to rotate the shackles between predetermined rotary orientations. Such orientation is necessary because the carcasses must be aligned in various different orientations as they engage the various processing machines at stations along the processing path. At the location of individual processing stations the turning blocks are usually confined between opposite parallel side guides to prevent accidental rotation of the turning blocks and thus the shackles and carcasses suspended therefrom. This inhibits any rotation of the carcasses as they are being processed through the machinery at the station.
In between the processing stations, the parallel side guides that prevent rotation of the shackles and carcasses may be interrupted. The side guides may also be interrupted where the turning block is engaged by turning features at a turning station to effect rotation of the turning block and shackle. More specifically, the turning block, in one exemplary embodiment, has a substantially square body with slots extending inwardly from its corners. These slots are configured and positioned to be engaged by one or more turning pins at a turning station positioned along the conveyor path. The turning pins may be attached to a plate and project into the path of movement of the turning blocks so that the pins engage the slots and rotate the turning blocks as the turning blocks move past the pins.
A yieldable indexing arrangement may be disposed between the carriage and the turning block to provide for indexed rotations to predetermined orientations of the turning block and shackle in, for example, ninety degree increments. The rotary orientations of the shackles are generally maintained by the indexing arrangement as the shackles move further along the track. This can be of particular importance at locations along the processing path where the lateral side guides are interrupted or not present. The yieldable indexing arrangement typically includes a spring biased ball and socket assembly that includes a cavity for holding the ball and spring on one of the relatively rotatable parts and a ball receiving recess or detent on the other relatively rotatable part. When the turning block is rotated to an indexed orientation, the ball is forced by the spring into the detent of the opposing part to hold the turning block, and thus the shackle and a carcass suspended therefrom, yieldably in the indexed orientation.
These prior art indexing arrangements are common and have been somewhat successful to ensure proper indexed rotations of the turning block and shackle. However, they can be problematic in food processing equipment because they include cavities, recesses, detents, and mechanical parts that may collect food material and are difficult to clean. Such indexing arrangements therefore can pose serious hazards of bacterial contamination of animal carcasses and parts processed along the processing path.
Accordingly a need exists to overcome or ameliorate at least one of the disadvantages of the prior art, and particularly prior art indexing arrangements in food processing equipment. There also is a need to provide alternative structures that are less cumbersome in assembly and operation and that moreover can be made relatively inexpensively and easily. Perhaps more salient, a need exists for an indexing arrangement that eliminates open cavities, recesses, detents, and mechanical parts that can collect food material and be a contamination hazard. Alternatively it is an object of the invention at least to provide consumers with a useful choice.